Electric switch



Feb. l0. l 925.

G. R. DQBBlNs ELECTRIC SWITCH Filed May s, 1922 lllllllllllllll/llllllll flllrlrllllllIllll/11111111111111111111111x '-S\ n; A

Patented Feb. 10, 1925.

UNlTED STATES PATENT OFFICE.

GEORGE R. DOBBINS, OF fLI-IAMBRA, CALIFORNIA, ASSIGNOR OE ONE-FOURTH TO I-I. H. HAMMOND AND ONE-FOURTH T0 VILLIAM B. H, MILLER, BOTH OF LOS ANGELES, CALIFORNIA.

ELECTRIC SWITCH.

Application led May 8, 1922.

To all 'whom t may concer/rt.'

Be it known that I, GEORGE R. DoeiNs, a citizen of the United States, residing at Alhambra. in the county of Los Angeles and State of California, have invented a. new and useful Electric Switch, of which the following is a specification.

This invention relates to an electric switch of a type that, when open, is latched so that 'the switch cannot be accidentally closed.

An objectof the invention is to produce a'switch of this type that is suitable for use in connection with a burglar o-r holdup alarm. It is desirable to place the switch, ffor closing an alarm circuit, in a position `that is convenient for operation and where it can be operated without the knowledge jof thieves who may be positioned close to the operator. This'switch is especially useful mounted in the floor of a bank or other place of business so that it can be operated by the foot of a bank `telleror any other person authorized to set oif the alarm. It will be .readily understood that a switch of this character, mounted in the floor, should be of such construction ythat accidental striking of it with the foot will not cause it to close the circuit 'which it controls.

The accompanying drawings illustrate the invention: v y i Figure 1 is a plan view of a switch constructed in accordance with the provisions 'of this invention, the switch arm being .shown in circuit-.breaking position in solid lines and being indicated in circuit closing position in broken lines.

Fig. 2 is a lsectional elevation on the irregular line indicated by 2 2, Fig. 1, the push button and contact arm being indicated in circuit-closing position in dotted lines.

Fig. 3 is a sectional elevation on the irregular line indicatedby 3 3, Fig. 2, the contact arm beingindicated in circuit-closing 'position in dotted lines.

Fig. 4 is a fragmental sectional elevation on the line indicated by 4 4, Fig. 2, the push button being shown depressed in dotted lines.

There is provided a floor plate 5 adapted to be secured by screws 6 to the floor or other surface in which the switch is mounted. Such floor or surface is indicated at 7. Secured by posts 8 to the plate 5 is a base plate e provided with .Statnary sigari? 901.1-v

Seral No. 559,406.

tacts 10 which are insulated from the plate 9 as indicated at 11. The contacts 10 are formed by the inner en'ds of binding posts 12 to which the wires of the electric circuit that is to be controlled are connected, as will be readily understood, so that the switch will be in the circuit. The contacts 10 are adapted to be engaged by a movable spring electric contact 13 adapted to bridge across the space between the contacjts 10. The intermediate portion of the Contact 13 is secured by a screw 14, insulated at 15, to one end of an arm 16 which-is pivoted near its other end at 17 to a pair of brackets 18 secured to the under face of the plate 5, as clearly shown in Figure 4.

The arm 16 is provided adjacent the pivot 17 with a downward projection 42 having a pair of oppositely disposed beveled faces 19, 20, lying at an angle to each other. The face 19, when the arm 16 is in the 0E position, as shown in Figure 2, engages a spring 21 secured at one end to the plate 9. When the arm 17 is in the on position the bevel face 20 engages the spring 21. To effect this the spring 21 is provided with portions 22, 23 lying at an angle to each other and alternately engaged bythe faces 19, 2O according` to whether the arm 16 is in circuit-opening or, circuit-closing positions. Thus the spring 21 will hold the arm 16 in either the off or on position and said spring also functions to snap the arm 16 to and from the contact closing position so as to avoid arcing between the contacts 10 and 13.

The plate 5 is provided with a recess 24, and pivoted at 25 to shift within this recess is an operating member 26 in the form of a disc provided with a projecting ear 27. The pivot 25 passes Vthrough the ear 27 The member 26 is provided with an upstanding boss 28 in which is slidably mounted the stein 29 of a push button 30. The

A stem 29 projects through a hole 31 in the plate 5 and is provided with an annular groove 32, which is suficiently wide to receive the marginal portion of the hole 31. The member 26 is provided with a slot 33 communicating with the hole 31 and constructed in an arc whose center is the axis of the pivot 25. The slot 33 is of less width than the diameter of the hole 3l and is slightly wider than the diameter of the reduced portion of the stein 29 so that, when 'CIL the push button is depressed to aline thel groove 32 with the slot 33, said push button may be moved out of the hole 31 into the slot 33 When the push button is in the slot 33, the under face of the plate 5 engages the shoulder 3e formed by theV lower wall ot the. groove 32, thus holding the push button depressed.

Then the push button is in its upper position the groove 32 lies above the level ot` the slot The push button 30, when in the hole 31, is yieldingly held against dcpression by Ya phmger 35 slidably mounted in the upper en-d o't a spring chamber 36 containing a. coil spring 3T which engages the inner end ot the plunger 35 to yieldingly hold said plunger in contact with the push button 30. The spring chamber 36 is provided with an internal shoulder 38 which engages in a longitudinal groove 39 in the plunger 35, said:Y shoulder 3S limiting outward movement ot the plunger.

lVhen the push button 30 is depressed and moved from the hole 31 along the slot 33 it strikes a projection 40 on the upper tace ot the arm 16, if said arm is in the circuitbreaking position shown in solid lines in Figure 2, so as to swing said arm downwardly to the position indicated by dotted lines to cause the face 19 to lea-ve the spring face 22 and to cause the face 2O to engage the spring face 23; whereupon sai-d spring will further actuate the arm 16 to move the contact 13 into engagement with the contacts 10 and hold it in that position. This of course closes the circuit in which the switch has been connected.

When it is desired to open the circuit and reset the switch, the push button 30 will be retracted alongthe slot 33 into the hole 31. In this movement the lower end ot the push butter. strikes a projection 41 on the upper lace ot the arm 16, said projection being on the opposite side ot the pivot 17 from the projection 40. Engagement o't the push button with the projection 41 swings the arm 1G upwardly to disengage the contact 13 from the contacts 10, thus opening the circuit. lVhen the push button is thus returned to position in the hole 31 it engages and depresses the plunger and, when released, is pushed upwardly by said plunger so as to bring the groove 32 out of registration with the slot 33.

From the foregoing it will be clear that, when the push button 30 is in its upper position in the hole 31, accidental striking of said button with the toot ot a person walking on the tloor, or otherwise` cannot move the push button into position to close the switch. If a person tread on the push button 30,7it will of course be depressed, but cannot effect closing of the circuit since it is also necessary to move the push button laterally.

In practice, the switch willwp'rerterably be installed in the floor in position to be readily operated byl the toot of a teller or other person authorized to set off an alarm connected in circuit withl the switch. As soon as the presence et thieves is noted by the teller or other person adjacent the switch, he will tread on the push button 30 to depress it, and he Ywill then move his foot laterally, to the right in Figure 1, to operate the switch in the manner hereinbetore described so as to energize the alarm. The switch may be advantageously employed in connection with the hold-up alarm disclosed in my copending application Serial N DAEOT, tiled May 3th, 1922, but may, ot course, be used with any othe-rsuitable alarm.

'I claim: Y

1. In an electric switch,Vv the combination 'of a push button mounted 'torendwise and lateral movements, means yieldingly holding the push button in one position, means locking the push buttonagainst lateral movement when .in said position, and means operable by lateral motion of the push button to close an electric circuit.

2. In `an electric switch, a moya-bly mounted operating member, a push ybutton mounted to move endwise in the operating member and to move laterally with said member, means to hold the push button depressed when the opera-ting member is moved, and means operable by the push button upon movement of the operating member to close an electric circuit.l

3. In ,an electric switch, a movably mounted operating member, a push button mounted to move endwise inY the operatingmember and to move laterally with said member,

means yieldingly holding the push button in one position, mean locking the push button against lateral movement when in said position, means to hold the push button depressed when the operating member is moved, and means operableby. the push button upon movement of the operating member to close an electric circuit.

4. In an electric switch, the combination of ay push button mounted'for endwisenand lateral movements, means vyieldingly holding kthe push button in 'raised position, means locking the push button against lateral movement when in said posit-ionmeans to hold the push button depressed when it is moved endwise and laterally, and mea-ns operable by lateral motion of the push button to close an electric contact.

5. In an electric switch, the combination of a pivoted arm, an electric contact carried by said arm, projections on the arm on opposite sides of the pivot, a second electric contact in position to be engaged by the first contact when the arm is in one position, means to yieldingly hold thearml with its Contact engaged with or disengaged from the second contact, a member mounted to shift laterally from a position Where it is disengaged from the arm into engagement With yone or the other of the projections according to Whether the arm is in contactengagi-ng or contact-disengaging position, and means to hold said member against such lateral shifting when said member is in the disengaged position.

6. In an electric switch, the combination of a pivoted arm, an electric contact carried by said arm, projections on the arm lon opposite sides of the pivot, a second electric Contact in position to be engaged b y the first contact when the arm is in one position, a third projection on the arm provided With beveled faces positioned at an angle to each other, a spring having faces positioned at an angle to each other, one of the spring faces engaging one of the arm faces when the arm is in contact-closing position, and the other spring face engaging the other arm face when the arm is in contact-disengaging position, a member mounted to shift laterally from a position Where it is disengaged from the arm into engagement with one or the other of the first named projcctions according to Whether the arm is in one or the other yof its positions, and means to hold said member against such lateral shifting When said member is in the disengaged position.

7. In an electric switch, the combination of an electric contact, means movable into dierent positions provided With an electric contact engageable with the first contact When said means are in one position, means movable into dierent planes and operable in one plane to o-ne position to operate the first means to close the contacts and operable in the same plane to another position to operate the first means to open the contacts, and means to prevent movement of the second means in the other plane.

Signed at Los Angeles, Cal., this 1st day of May 1922.

GEORGE R. DOBBINS. lVitnesses:

GEORGE H. HILEs, L. BELLE WEAVER. 

